Srikanth Keesara, Tewksbury US

Srikanth Keesara, Tewksbury, MA US

Patent application number

Description

Published

20090232005

IP Network and Performance Monitoring Using Ethernet OAM - Network and performance monitoring in a link state protocol controlled Ethernet network. A first node receives a network layer monitoring command from a network layer monitoring requestor. The monitoring command is directed to a second node. The first node resolves the network layer monitoring command into one or more Ethernet OAM command(s); The first node sends the Ethernet OAM command(s) to the second node, receives the results of the Ethernet OAM command(s) from the second node; and returns the results of the Ethernet OAM command(s) in the form of a network layer response to the network layer monitoring requestor. Furthermore, network layer monitoring commands may be one or more performance monitoring commands, and the Ethernet OAM commands can include Y.1731 commands. An IP flow can be adjusted between the first node and the second node in response to the network layer response returned to the network layer monitoring requestor.

09-17-2009

20090232006

Continuity Check Management in a Link State Controlled Ethernet Network - An OAM link trace message is sent from a source node to a target node in a link state protocol controlled Ethernet network. The link trace message using an 802.1ag format except, as a destination address, it uses either the unicast Ethernet MAC node ID of the target node, or the multicast destination address of the service instance. A method of network topology verification in a link state protocol controlled Ethernet network checks the link state protocol database at a node to ascertain the control plane topology view of at least part of the network. It then executes one or more Ethernet OAM commands from the node to ascertain the data plane topology view of the same part of the network. The control plane topology view of the network is compared to the data plane topology view of the network to see if they match. An error is flagged if they do not match.

09-17-2009

20090234969

Automatic MEP Provisioning in a Link State Controlled Ethernet Network - Ethernet OAM MEPs are automatically configured in a link state protocol controlled Ethernet network. A node operating in the link state protocol controlled Ethernet network receives a Link State PDU (LSP) containing a TLV having a MEP associated with the Ethernet MAC node ID of a second node in the link state protocol controlled Ethernet network, where the path between the first and second node includes a plurality of links. The node updates a forwarding table to indicate an association between the MEP ID and a Ethernet MAC node ID of the second node. An Ethernet OAM maintenance endpoint is produced in a link state protocol controlled Ethernet network by hashing a Sys-ID to produce a MEP; storing the MEP in a TLV; and forwarding the TLV over the link state protocol controlled Ethernet network in an LSP.

09-17-2009

20090282291

INTERNAL MAINTENANCE ASSOCIATION END POINT (MEP) FOR SHARING STATE INFORMATION - A network node includes a central processor card and a plurality of line cards. Each line card generates a maintenance association end point (MEP) entity that can respond to connectivity fault management (CFM) frames. The MEP entity on each line card periodically generates and transmits a multicast connectivity check message (CCM) to the other line cards in the network node. The CCM includes a card-information TLV and, optionally, a trunk-status TLV. Card-information TLVs include the slot number and card type of the transmitting line card. Trunk-status TLVs include the trunk state of each trunk supported by the transmitting line card. The line cards of the node consider a given line card to be down when three consecutive CCMs from that line card are missed. In response to recognizing a down line card, the other line cards can initiate an action, such as determine the trunks supported by the down line card and trigger a trunk switchover.

11-12-2009

20110255417

AUTOMATIC MEP PROVISIONING IN A LINK STATE CONTROLLED ETHERNET NETWORK - Ethernet OAM MEPs are automatically configured in a link state protocol controlled Ethernet network. A node operating in the link state protocol controlled Ethernet network receives a Link State PDU (LSP) containing a TLV having a MEP associated with the Ethernet MAC node ID of a second node in the link state protocol controlled Ethernet network, where the path between the first and second node includes a plurality of links. The node updates a forwarding table to indicate an association between the MEP ID and a Ethernet MAC node ID of the second node. An Ethernet OAM maintenance endpoint is produced in a link state protocol controlled Ethernet network by hashing a Sys-ID to produce a MEP; storing the MEP in a TLV; and forwarding the TLV over the link state protocol controlled Ethernet network in an LSP.

10-20-2011

20120063451

SHARED VIRTUAL TUNNELS SUPPORTING MAC LEARNING IN COMMUNICATION NETWORKS - Embodiments herein include systems and methods for providing a mechanism for tunneled data transport within a dual homed access network. A tunnel manager, at a first network connectivity device in a transport network, identifies the transport network configured to interconnect at least two access networks for transporting data traffic between one or more end stations connected to the access networks. The first network connectivity device is coupled to a first access network. The tunnel manager identifies a second network connectivity device. The second network connectivity device is coupled to the first access network to provide the first access network dual homed access to the transport network via the first and second network connectivity devices. The tunnel manager creates a virtual tunnel that connects the first and second network connectivity devices to a third network connectivity device across the transport network. The virtual tunnel defines a same virtual tunnel having multiple paths such that the third network connectivity device learns a single virtual tunnel for device address learning.

03-15-2012

20120063453

MULTICAST TREE DISCOVERY USING 802.1ag - Methods and apparatus provide for a network device(s) employing tree tracer processing of a data packet(s) and/or a response(s) in order to discover and graphically represent all the paths within a hierarchical tree of network devices for multicast traffic flows. Specifically, a first network device receives a data packet. The data packet provides a multicast target MAC address. The first network device forwards the data packet to a plurality of network devices, where each of the plurality of the network devices belong to a multicast group identified according to the multicast target MAC address. Based on receipt of the data packet, the first network device generates and transmits a first response to a source of the data packet. The first response indicates a placement of the first network device with respect to a hierarchical tree of the plurality of network devices belonging to the multicast group.

03-15-2012

20120063465

ACCESS NETWORK DUAL PATH CONNECTIVITY - A transport network employs dual homing to an access network to provide connectivity from multiple network switches. Dual homing is a mechanism by which an access network employs pair of switches in the transport network as if it were connecting to a single device. Conventional arrangements for defining multiple paths from a transport network to an access network suffer from the shortcomings of potential routing loops, increased hops to the access network, and inability or inconsistency with forwarding to different types of access networks, and may involve redirecting traffic absent faults in the access network. The dual homed network switches identify the type of access network and perform switching logic corresponding to the access network type to provide comprehensive dual-homed support to the access network independently of the type of transport employed in the access network, and employ redirection only if there is a fault in the access network.

03-15-2012

20120113817

Multicast Network Diagnostics - A Shortest Path Bridging (SPB) network provides a multicast traceroute using network identifiers such as IP addresses for the source and destination (multicast group). The network identifiers, which are based on layer 3 (IP) designations of the traced multicast group, are mapped to a network identifier of the multicast group (corresponding to a layer 2, or MAC address) and an associated Virtual Local Area Network (VLAN) which is used to transport the packets belonging to the multicast flow. Therefore, an operator issuing the traceroute command need not be familiar with the layer 2 concepts of the network, but rather need only supply the layer 3 (IP address) designations of the concerned entities.

05-10-2012

20120243539

USAGE OF MASKED ETHERNET ADDRESSES BETWEEN TRANSPARENT INTERCONNECT OF LOTS OF LINKS (TRILL) ROUTING BRIDGES - Techniques herein include systems and methods that extend functionality of transport networks including Transparent Interconnect of Lots of Links (TRILL) networks. Techniques include using a portion of information within transport device address encapsulation headers for purposes other than identifying source and destination device addresses. The system masks a portion of bits in an address header for an address lookup in forwarding tables of a transport network node. The remaining bits in the address field(s) become free bits that can be used for a variety of application purposes, such as flow identifier selection. By using information fields that already exist in encapsulation headers, such techniques provide additional information without increasing packet size or requiring new protocols. Embodiments can combine Equal-cost multi-path routing (ECMP) functionality, Reverse Path Forwarding (RPF) checks, and Time to live (TTL) protection at the same time.

09-27-2012

20120243544

USAGE OF MASKED BMAC ADDRESSES IN A PROVIDER BACKBONE BRIDGED (PBB) NETWORK - Techniques disclosed herein include features and methods that extend functionality of provider networks including Provider Backbone Bridges (PBB) networks. Techniques include using a portion of information within Ethernet address encapsulation headers for purposes other than identifying source and destination device addresses. The system limits a number of bits in an address header that should be considered by a provider network node when doing an address lookup in forwarding tables of a provider network node, such as by masking the portion of bits or otherwise disregarding that portion of bits during address lookup. The remaining bits in the address field(s) become free bits that can be used for a variety of application purposes, such as flow path selection. By using information fields that already exist in the Mac-In-Mac (MIM) encapsulation header, such Techniques provide additional information without increasing packet size or requiring new protocols.

CONVEYING THE VLAN/L2 VSN/BRIDGING-DOMAIN OF THE INCOMING INTERFACE (IIF) WHEN TRANSPORTING MULTICAST TRAFFIC OVER A SHORTEST PATH BRIDGED (SPB) NETWORK - Techniques disclosed herein include systems and methods for improving multicast traffic operations in a Shortest Path Bridging (SPB) network by conveying bridging domain information of an incoming interface (IIF) when transporting multicast traffic over the SPB network. Techniques disclosed herein include modifying encapsulation packet header information of existing Mac-In-Mac fields to convey additional information that can be interpreted at edge nodes by modifying edge node interpretation of multicast data. Specifically, the value of the I-SID in the BMAC-DA field can be set to be different from the I-SID value in the I-TAG field. Carrying the L2 VSN I-SID value in the I-TAG allows the Egress BEBs to determine which VLAN/L2 VSN/Bridging-Domain of the IIF is in use, and then modify or preserve underlying header information accordingly.

03-28-2013

20130077625

EXTENSION OF THE INTERPRETATION AND DEFINITION OF THE IS-IS TLV/SUB-TLV - Techniques disclosed herein include systems and methods for improving efficiency of multicast state generation within Shortest Path Bridging (SPB) networks. Techniques include using an IS-IS TLV structure with new multicast state computation rules for SPB Networks. SPB Networks use a TLV field for the I-SID Address (and equivalent TLV fields defined in different IETF/IEEE drafts) and node nicknames to signal information that is used to compute a multicast state required to provide L2 Services over a given SPB Network. The I-SID Address TLV is set or filled to carry various items of information. These items of information can include Backbone Media Access Control (B-MAC), Virtual Local Area Network Identifier (VID), I-SID[Transmit, Receive Bit], etc.

03-28-2013

20130077626

SEPARATION OF EDGE AND ROUTING/CONTROL INFORMATION FOR MULTICAST OVER SHORTEST PATH BRIDGING - Techniques disclosed herein include systems and methods for providing a scalable solution to transmit edge IP Multicast sender information in a Shortest Path Bridging (SPB) network. Control information is exchanged between Ingress Backbone Edge Bridges and Egress Backbone Edge Bridges using Multicast Flow Specific and type-length-value (TLV) structures, or other control messages, to announce available multicast streams at ingress nodes within the SPB network. Such exchanges of control messages trigger sending SPB specific Intermediate System To Intermediate System (IS-IS) TLV control message with path computation information via IS-IS control messages. This second set of control messages is exchanged within the SPB network and includes source-specific multicast stream information that is used by Backbone Core Bridges to establish a multicast forward state and compute multicast forwarding paths. Multicast data traffic can then be transmitted through the SPB network using a one-to-many distribution model.

03-28-2013

20130077627

METHOD AND APPARATUS FOR ROUTING MULTICAST DATA ACROSS MULTIPLE MULTICAST ROUTING DOMAINS CONNECTED BY A SHORTEST PATH BRIDGING (SPB) NETWORK - A method and apparatus for routing multicast data across multiple multicast routing domains connected by a shortest path bridging (SPB) network is presented. A Shortest Path Bridging (SPB) edge router of an SPB network connected to a PIM network is configured as a Rendezvous Point (RP). A message is received at the RP, and in response, the RP forms a first data structure including multicast sender information. The RP floods the SPB network with a second message containing the first data structure, allocates an Identifier (ISID) to the multicast stream, and sends a second data structure with sender information. An edge router with multicast receive interest responds with the second data structure with multicast receive interest information. As a result, a receiver in a second network has knowledge of devices in a first network such that multicast traffic is able to be routed between different networks connected to the SPB network.

MULTI-LAYER NETWORK DIAGNOSTIC TRACING - A network management and monitoring application employs diagnostic messages for confirming network path connectivity and identifying and locating connectivity faults. Diagnostic messages similar to conventional “ping” and “traceroute” messages traverse the network along a prescribed path for which diagnostic feedback is desired. The application receives and analyzes return messages sent from network entities along the path to ascertain connectivity issues on the path. The application receives layer 3 identifiers such as IP addresses, however performs diagnostic operations such as continuity checks based on layer 2 identifiers such as MAC (Media Access Control) identifiers because certain network entities operate on L2 identifiers and would otherwise evade a continuity check based on layer 3 identifiers. The monitoring application therefore performs continuity diagnostics such as ping and traceroute operations using L2 identifiers, therefore pinpointing problems with an L2 network forwarding entity such as a bridge that lies between L3 entities such as routers.

05-23-2013

20130136122

USING MULTIPLE IGMP QUERIERS IN A LAYER 2 NETWORK - Techniques disclosed herein include systems and methods for extending an IGMP broadcast domain (multicast domain) across a transport network without implementing IGMP snooping within the core of the transport network, yet while providing efficient transport within the core of the transport network. Techniques include dividing a single IGMP interface into multiple IGMP domains or sub-domains. A separate Querier is then elected for each IGMP domain using the single IGMP interface. Edge nodes of the transport network can be configured as the multiple IGMP Queriers, and then re-distribute sender information via a separate routing protocol. Requests can then be sent using the transport network control messaging or routing protocol instead of IGMP snoop messages to advertise multicast data streams in between the multiple IGMP domains (across the transport network). Traffic can then delivered efficiently between isolated access networks of a single Service Layer 2 Network.

05-30-2013

20140075041

SYSTEM AND METHOD FOR DATA STREAM MIRRORING - A mirroring configuration employs an alternate usage of an existing messaging protocol and mechanism for propagating mirroring control for remote mirroring of data streams. A source routing entity, i.e. a router or switch through which the mirrored stream passes, identifies the stream as available for monitoring. The enabled stream propagates from a source network device, typically from a router port, to a mirroring destination in addition to the addressed destination. A stream identifier emulates an identifier from an alternate usage, such as a multicast group identifier for a multicast protocol, and activates mirroring by inserting the stream identifier in publish and join messages of the multicast protocol.

03-13-2014

20140086100

Multi-Chassis Cluster Synchronization Using Shortest Path Bridging (SPB) Service Instance Identifier (I-SID) Trees - A method, apparatus and computer program product for providing synchronization of a multi-chassis cluster using SPB I-SID trees is presented. A plurality of network devices are defined for making up a single cluster. Each network device of the cluster is configured with a same cluster Identifier (cluster ID) and each network device of the cluster signals an Service Instance Identifier (I-SID). At least one ISID multicast tree is generated, each one of the at least one multicast tree rooted at one node of the cluster. Cluster synchronization messages are exchanged between the network devices of the cluster using the at least one multicast tree.

03-27-2014

20140086244

Method and Apparatus For Performing Multicast Backbone Media Access Channel (BMAC) Header Transformations - A method, apparatus and computer program product for performing multicast Backbone Media Access Channel (BMAC) header transformations is presented. A packet having a header is received at a network node. The header is modified to produce a packet having a modified header by replacing an original value inside the header with a less granular value. The packet having a modified header is forwarded into a transport network.

Architecture For Virtualization And Distribution Of Routing Information Used In A Transport Network - A method, apparatus and computer program product for distribution of routing information used in a transport network is presented. In a transport network having a plurality of edge devices and core devices, a main instance of a protocol is used for shortest path and tree computation. A multicast tree is defined per Virtual Services Network (VSN) to distribute Link State Data Base (LSDB) updates that only apply to members of said VSN. Multicast trees are built using a secondary instance of the control protocol LSDB and wherein each VSN multicast tree represents a separate instance of the secondary instance of the control protocol LSD. LSDB updates are distributed that only apply to members of the VSN using the multicast tree for the VSN.